Lake John, located in Cowdrey, Colorado, is a state-regulated water resource popular for its recreational activities such as fishing and wildlife viewing. The earth dam, standing at 25 feet high and completed in 1957, creates a reservoir with a storage capacity of 16,128 acre-feet and a surface area of 612 acres. The dam's spillway, an uncontrolled type with a width of 40 feet, can handle a maximum discharge of 2800 cubic feet per second.

Despite being classified as having a significant hazard potential, Lake John is currently in fair condition as of the last inspection in September 2019. The dam's emergency action plan was last revised in January 2016, and the risk assessment for the site is moderate. With its picturesque location in Jackson County and its crucial role in supporting fish and wildlife habitats, Lake John serves as a vital water resource for the region, attracting water and climate enthusiasts alike to appreciate and protect its natural beauty and ecological significance.